Factorial.py

# To take input from the user
num = int(input("Enter a number: "))

factorial = 1

# check if the number is negative, positive or zero
if (num < 0):
   print("Sorry, factorial does not exist for negative numbers")
elif (num == 0):
   print("The factorial of", num, "is", 1)
else:
   for i in range(1,num + 1):
       factorial = factorial*i
   print("The factorial of",num,"is",factorial)